1. Field:
The present invention is directed toward a scope, notably a rifle scope, having a motor-powered zoom lens assembly.
2. State of the Art: A zoom lens assembly ("zoom") is a mechanically operable assembly of lenses that is typically associated with some other optical device to vary the magnification of the image provided by the device. Zoom lens assemblies allow a user to "zoom," or quickly and continuously vary the magnification of the device between a particular minimum and maximum magnification. While retaining the image in the eyepiece of the optical device, the user can zoom in on the image at a relatively higher power or zoom out to provide a lower power and a wider field of vision. Zoom lens assemblies are commonly used in association with video, movie, and snapshot cameras. On such devices, the zoom lens assembly is often motor powered.
Certain binoculars are available which include a powered zoom lens assembly. These binoculars include an electronic switch or button located within easy reach of the user's fingers while holding the binoculars to the user's eyes. Such zooms allow the viewer to retain the selected image in the field of view while zooming to the desired magnification. With such binoculars, the motor, batteries, and other elements of the zoom assembly are mounted above and between the main optical elements.
Certain firearm scopes come equipped with a variable magnification lens assembly located at the eyepiece. To vary the magnification, the shooter is required to remove the firearm from the shooting position and rotate the eyepiece to the desired magnification. Such movement results in the shooter losing the target in the field of view of the scope. In addition, the target may sense the movement and the shooting opportunity may be lost.
Once the shooter has located his target within the field of view of the scope, it would in many instances be helpful for the shooter to zoom in to the target without removing the target from the field of view. The shooter may wish to verify that he is shooting an animal of the proper sex or that the animal has certain characteristics, such as size of rack, to make it a desirable trophy. In a military or police sniper setting, the shooter may want to positively identify his selected target.
In a firearm scope setting, extraneous mountings of motors or lens assemblies such as used with binoculars would be disadvantageous or unacceptable. Shooters are unaccustomed to having anything protruding from the side or the top of a scope. It is preferable for the rifle and scope to be as compact and lightweight as possible. Any protrusions from a scope would create additional possibility for the scope to be struck or damaged. In addition, many shooters may find such protrusions aesthetically unacceptable.
There remains a need for a powered zoom lens assembly which is mounted to be optically aligned with the main body of the scope and to present an outer appearance generally consistent with the shape of and aligned with the scope. Such an assembly would preferably be lightweight and powered by a motor and power supply in a compact assembly mounted to and conforming to the shape of the scope. Additionally, such an assembly would include a switching mechanism easily operable by the user without the necessity of the shooter losing the target image in the field of view.